An audit of genetic testing outcomes and sociodemographic factors of patients who received genetic counselling for hereditary breast cancer through the Division of Human Genetics

Abstract

Breast cancer remains a leading cause of cancer-related deaths globally, with incidence rates steadily rising in South Africa over the past two decades. Despite efforts such as screening programs and predictive testing, early detection and treatment are hindered by delayed diagnoses, limited healthcare access, and socioeconomic challenges, particularly in low- to middle-income countries. Micro-level assessments, such as clinical audits, are essential to identify gaps and improve care strategies. This study aimed to construct a patient profile of genetic testing outcomes and sociodemographic factors for individuals who underwent genetic counselling for hereditary breast cancer over six years (September 2018–January 2024) at the National Health Laboratory Services (NHLS), Braamfontein. Data from 619 patient files were extracted from the departmental REDCap database. Extracted variables included demographic, personal, family, and medical history, alongside genetic testing uptake and outcomes. Statistical analyses included descriptive statistics, Chi-squared tests, t-tests, ANOVA, and multiple regression modelling. The study included 619 participants, with 594 (95.96%) eligible for diagnostic testing and 25 (4.04%) eligible for predictive testing. Diagnostic testing participants were predominantly of Black ancestry, state-sector patients, and urban residents, while predictive testing participants were mainly White, private-sector patients. Diagnostic testing uptake was 78.96%. Sociodemographic factors influenced testing uptake and outcomes; younger age and employment increased acceptance, while Black ancestry and older age were linked to fewer actionable results. While predictive testing uptake was 88.00%, the number of proband relatives presenting for predictive testing relative to those eligible was notably low. Findings suggest targeted education and research can improve awareness and genetic testing, addressing South Africa's breast cancer burden.